4) Older spelling of Turkey should also be accepted
5) Country names should always be capitalized.
Also considering your instructions say all countries (and you don't specify a timeline) then also included should be USSR, Yugoslavia, Czechoslovakia, and USA itself. Possibly others.
2) Papua New Guinea, not just New Guinea
3) Congo is a generally accepted type in for DNC
4) Older spelling of Turkey should also be accepted
5) Country names should always be capitalized.
Also considering your instructions say all countries (and you don't specify a timeline) then also included should be USSR, Yugoslavia, Czechoslovakia, and USA itself. Possibly others.